Nah mine doesn't have 'issues' as such running 91, it's just been on it for a long time it seems and the 98 we use here (Shell V-Power mostly) does wonders for these engines. It's far more punchy on the throttle and with all of the work I've been doing on the fuel injection rails and such, they're in need of a run through with the 98 octane as it also helps clean as it burns. It's not a night and day difference going from 91 to 98, but over time it's doing wonders for the engine. Remember that you can't just whack in a tank of a higher octane gas and expect miracles - it takes time to work through the system and, in my case, 'clean' the shit out, so to speak.

My aim is to run a tank or two of 98 through, then switch back to 95 for normal running. Once I change down to 95, I'll run some injector cleaner through on the first tank. That should get it all sorted. As a point of note, I've actually gained a little in economy since running this first tank of 98 through, much to my surprise.

Gave the 730 a clean on the weekend, snapped some pics while I was at it. I tried using those armorall wips on the black plastic guards and trims but it attracted the fine dust in the air and all of the black on the car turned a very strong BROWN colour... did not look good at all. I'm going to have it properly polished & waxed some time this week. Almost finished sorting out the vacuum leaks and this weekend it gets a new transmission filter & fluid wash, fuel filter and maybe some center link bushings (desperately needs those!).

Been running it on 98 octane for a week now, it's made a hell of a difference, much to my total surprise. Recommends 95 octane as a minimum but it's been run on 91 for far too long, and fucked if I know how it was treated prior to my owning it. Poor thing :(

Also, now that I've finished my armrest drink container conversion, I've started working on a way to add a concealed folded 'throw blanket' in there too. I found this smaller sized blanket at a damn good price on the weekend (it's soft as silk) and since the weather's getting cold I figured it'd be a nice touch to add. There's space in a concealed leather-flap-covered spot behind the armrest container, but that would mean the armrest would have to STAY down all the time, because it won't close with the blanket in there. Still, looks awesome even if I do it that way.

Will get pics some time.

BMW's come with knock and ignition sensors that take note when you run low-octane fuel and compensate accordingly. Trust me, you could run 87 and not hurt anything, you'd just severely hinder performance.

Anti-Knock Index (AKI)
In most countries, including Australia and all of those in Europe, the "headline" octane rating shown on the pump is the RON, but in Canada, the United States and some other countries, like Brazil, the headline number is the average of the RON and the MON, called the Anti-Knock Index (AKI, and often written on pumps as (R+M)/2). It may also sometimes be called the Pump Octane Number (PON).

BMW's come with knock and ignition sensors that take note when you run low-octane fuel and compensate accordingly. Trust me, you could run 87 and not hurt anything, you'd just severely hinder performance.

Yeah but retarding the ignition isn't really a GOOD thing for the car. Even on 91 (your 87 I believe) there's significant degree of knock and power loss with a lot of these M60/M62's, not to mention a sometimes drastic lack of power under higher load combined with poorer mileage (hell even I've seen an improvement in mileage going from 91 to 98 on my little 3.0L). The wide general consensus is to always run 95 (89 for you?) as an absolute minimum to ensure better longevity of the engine. Even some folk from BMW had a big talk about this a while back and came to the same conclusion : go ahead and run 91, the car will compensate for it, but 95/98 is always the way to go for the health of the engine over time.

Since switching to 98, my M60's become all kinds of different. It sounds a bit different to before and it's just performing generally better. We'll see if running some injector cleaner through helps (I don't believe the injectors have been touched in the cars life - 16 years) but I may consider having the injectors professionally serviced and cycled at some stage.

At the end of the day, I'm driving a 'premium' car so to speak, so spending an extra 10 bucks on higher quality fuel isn't really a big deal. I suppose if someone's put off by having to pay more for the better fuel in one of these cars, they probably shouldn't be driving one in the first place :P

A significant improvement then. I was averaging 130 to 140km at best per quarter tank. Since switching to 98 octane, that has suddenly changed to a bit over 200km per quarter tank... That's fucking amazing. Effectively, the extra money spent on the higher octane fuel is totally surpassed in value by the huge improvement in economy.

All of this with 'city' driving too - no highways or anything. If this kind of economy holds up through the next tank of 98 too, then I'm looking at over 800km off a single 80 litre tank. To put that in perspective, my 6 cylinder jeep barely tops out at 400km (at BEST) on a 60 litre tank with the same fuel. To jump up to a 2 tonne V8 and DOUBLE the distance travelled for only 25% more fuel? Insane.

Maybe that's not too impressive to you but, I can't wrap my head around the sheer difference it's made. Best guess, the injectors must just have been in an utterly awful state.

Yeah but retarding the ignition isn't really a GOOD thing for the car. Even on 91 (your 87 I believe) there's significant degree of knock and power loss with a lot of these M60/M62's, not to mention a sometimes drastic lack of power under higher load combined with poorer mileage (hell even I've seen an improvement in mileage going from 91 to 98 on my little 3.0L). The wide general consensus is to always run 95 (89 for you?) as an absolute minimum to ensure better longevity of the engine. Even some folk from BMW had a big talk about this a while back and came to the same conclusion : go ahead and run 91, the car will compensate for it, but 95/98 is always the way to go for the health of the engine over time.

Since switching to 98, my M60's become all kinds of different. It sounds a bit different to before and it's just performing generally better. We'll see if running some injector cleaner through helps (I don't believe the injectors have been touched in the cars life - 16 years) but I may consider having the injectors professionally serviced and cycled at some stage.

At the end of the day, I'm driving a 'premium' car so to speak, so spending an extra 10 bucks on higher quality fuel isn't really a big deal. I suppose if someone's put off by having to pay more for the better fuel in one of these cars, they probably shouldn't be driving one in the first place :P

I run 91 octane (98 for you) as I chipped the car and I'm required to, otherwise I'll detonate. Besides, I knew what I was getting into when I chipped it, so premium it is. I don't mind it, it's literally an extra $3 everytime I fill up. As for injector cleaner, my personal mechanic says it's about as useful as pissing in the tank. Never tried it myself.

I run 91 octane (98 for you) as I chipped the car and I'm required to, otherwise I'll detonate. Besides, I knew what I was getting into when I chipped it, so premium it is. I don't mind it, it's literally an extra $3 everytime I fill up. As for injector cleaner, my personal mechanic says it's about as useful as pissing in the tank. Never tried it myself.

Also, eyelids:

That's a tidy bitch now, good work!

It's interesting that your 'personal mechanic' says injector cleaner is useless... I've always taken particular concern for what the actual DRIVERS of these cars have to say, and it would seem to be the general consensus that injector cleaner (specially on these older engines where buildup is a common issue) does wonders. Sure it's subjective mostly; "More power" "Better throttle response" " No shudder or misfire at X speed". But there are a few people who have done comparisons before and after regarding their fuel mileage and found that post-injector cleaner, there's a clear and unmistakable improvement, sometimes small, sometimes drastic.

As far as I'm concerned, at $8 for a bottle and with THAT kind of positive feedback from real everyday drivers like myself, it can't hurt to just give it a shot. And given that my car's going on 16 years old and I can't really be sure how it's been treated prior to my loving it up, I'll do anything I can to keep it happy. If I took out my injectors and they were cloaked in shit, I wouldn't even bat an eyelid... I'd probably just go "Oh ok" and get 'em cleaned. I mean, LOOK at this;

Doesn't that just make your balls tingle? I'll let you know how mine fares with the injector cleaner run through it. You never know!

Oh come on now, you know precisely what I mean. Most of the time the people who drive these cars in their daily lives are more interested in getting down to the nuts and bolts of why X or Y goes wrong and how it came to be, rather than a typical mechanics' line of thinking of "X is broken, just replace it and see if that works".

It's like my transmission or Idle problems... The dealer / mechanic both went straight to "Rebuild the transmission", whereas everyone else is recommending replacing the tranny filter and fluid. I've just done that replacement and it was a night and day difference - instantly fixed. Idle problems I was having? Replace the ICV. Nope, disconnected it, blasted it with some parts cleaner and that's good as new too.

So yes most drivers ARE idiots, but a lot of them - specially with these BMW's - take a real interest in understanding the inner workings of their engines and at the end of the day, I would trust their advice combined with my own research over just about any dealer or mechanic at this point. For the cost of a basic service from the mechanic, I've already cleaned and/or rebuilt half of the components within my engine at little to no cost to me, and it's done wonders for how she performs. Couldn't have done it without those 1% who weren't idiots!!

The best part is that before this BMW, I really had no experience maintaining cars, so through these guys and their advice, I've been saving shitloads of money and learning things I never would have if I'd just stuck to having a shop do the work all day long. I'm stoked.

Is my mechanic the only ones who try to offer quality parts over cheap shit and always tries to meet the customers budget.

Needed new spark plugs and wiring cause oil got all over cause valve gasket needs to be replaced. Told them needed new plugs and wiring cause of oil all of them and they said you just need what you said and a new valve gasket. Hour and a half later car is ready and good to go. They even let me know that when i come for inspection thier Mechanic wrote down notes saying that I needed a new Cat and If I get one myself they will just charge me an hours labor. They even encourage bringing your own parts as you'll meet your part budget and they don't have to call up to get the part.

Not all mechanics are shit heads, If you find a good one that operates under Good Year's name or etc you may find someone you can trust. Shop around for mechanics. Even the good ones can fuck up once in a while but when they do they will reimburse in some form of way.

My dad had been eyeing this longbed, single cab, 4-wheel-drive Dakota for a while now, it was marked $1800 at a car lot. The guy marked it down to $1688 a while back, and my dad sold his Sportster today so we decided to go look at it:

Then he bought it for $1500. Smooth running truck, 318, 4x4, it's the new replacement for the Ram Charger.